This invention relates to closed circuit visual display systems used with vehicular simulation devices for training operators such as pilots, drivers, etc. More particularly, the invention relates to terrain model boards viewed by the closed-circuit television camera of such a system and further relates to a method of fabricating such terrain model boards to facilitate disassembly, alteration, and/or repair of the terrain model board.
Visual display systems used with aircraft simulation and comprising a closed-circuit television system in which a television camera is moved about a three-dimensional terrain model have gained widespread use in the field of aircraft simulation. Apparatus and techniques for controlling camera movement, as well as transmitting and displaying the image of the terrain model are disclosed in U.S. Pat. Nos. 2,959,779; 3,052,753 and 3,670,426. The three-dimensional model board which is scanned by the TV camera as the camera follows a simulated course of flight determined by the student pilot as the trainee pilot "flys" the simulation aircraft is fashioned painstakingly with rigorous adherence to correct scale factors so that the trainee can properly judge altitude, altitude rates, slant range, closure rates, etc. The terrain model board generally comprises a multiplicity of separate panels which when joined together create a large section of terrain that may include mountains, rivers, buildings, airports, runways, etc., and may have an overall dimension on the order of twenty feet by forty feet. The scale of such a terrain model board is so large that a 20.times.40 foot model might easily represent a section of terrain on the order of six miles by twelve miles. Because of this large scale factor, it will be appreciated that if a pilot trainee was performing a maneuver that would in real life bring his aircraft within 200 feet of the ground, the television probe or lens would be "flying" above the model board at about 1.6 inches. Similarly, if the pilot were to be performing a maneuver, such as landing, that would bring his eyepoint within twenty feet of the ground, the television probe or lens would only be 0.16 of an inch away from the model board. Thus, it can be seen that as the camera probe moves rapidly along the model board at such close distances, a slight mistake on the part of the trainee pilot or an irregularity in the model board could result in the probe making contact with or "crashing" into the model board. Such crashing almost always results in damage to either the camera probe or the model board. Even though the detail terrain model boards are by no means inexpensive, when compared to the cost of a camera probe it is much more desirable that any damage that results because of the crash be experienced by the model board and not the probe. It is also not uncommon, for various reasons that a portion of the model board be altered to simulate a different terrain or to reflect different and new buidings, etc. It may also be desired to completely disassemble a terrain model board so that the entire simulator complex can more readily be moved to a new location. Consequently, for purposes of repair, alteration and easy assembly and disassembly it is often necessary to remove one or more of the individual panels which make up a terrain model board. Therefore, it is an object of this invention to provide a terrain model board which is built up from a multiplicity of easily assembled and easily separable panels.
It is a further object of this invention to provide an improved method of joining a multiplicity of individual panels making up a terrain model board to provide for quick and inexpensive disassembly of the individual panels making up the terrain model board.
It is still another object of the invention to provide a new method of assembling a multiplicity of panels to make up a terrain model board which allows easily assembly and disassembly without requiring special tools.
To accomplish the above mentioned objects as well as other objects which will become evident from the following drawings and detailed description, the present invention discloses a three-dimensional terrain model board and method of construction which comprises the steps of locating or placing the panels to be joined at a small spaced distance from each other such that the panels when viewed together appear as one larger continuous area. A packing strip is then inserted in the spaced distance or seam between adjoining panels. This packing strip is in contact with extended edges of adjoining panels and below the surface of the panel containing the simulated terrain. An adhesive or elastic compound is then used to fill the seam up to the level of the terrain surface to provide an overall continuous simulated terrain surface. The packing strip includes a cord such as a string or wire which is cemented to the top surface so that a panel may be readily removed from the composite terrain model board by simply gripping the cord and pulling up and along the seam thereby cutting through the seam filling compound and separating the panel.